1. Field of the Invention
The present invention relates to an operation management system and, in particular, to an operation management system having the function of directly displaying, on a machine tool, a work instruction based on operation management information.
2. Description of the Related Art
In general, machine tools operating in a factory are connected to a network to be managed. As a system operating in a factory, there are, for example, an operation monitoring system for monitoring the operation status of the whole factory based on information on machine tools including the operation statuses of the machine tools connected to a network, and an operation management system for determining the operation schedule of machine tools based on information on production plans, manpower, and facilities. The operation monitoring system and the operation management system are not independent of each other, and the operation management system adjusts a schedule in real time based on information collected by the operation monitoring system.
In addition, with the advanced automation of machine tools, an operator has no need to stay in front of the machine tools during the machining of the machine tools. Therefore, in a factory, an operator may concurrently perform various work processes (such as the replacement of workpieces and an instruction to start driving) with a plurality of machine tools. In such a situation, an operation management system may manage not only the operation schedule of machine tools but also a schedule for each operator as to what order the operator operates a plurality of machine tools.
For example, Japanese Patent Application Laid-open No. 2002-373015 discloses a system for correcting an operation schedule in real time based on information obtained from an operation status to notify an operator of the order of conducting setup work.
In a situation in which various kinds of products are produced in small amounts, an optimum schedule for the operation of machine tools changes not only with daily production contents but also with sudden failures in facilities or delay in operator's work. Accordingly, in order to conduct work under an appropriate schedule, an operator has need to pay attention to a change in the schedule at all times and periodically confirm the schedule.
On the other hand, in a situation in which the same kind of products are produced in large amounts, an operator conducts work under the same schedule day by day. In such a situation, the operator does not feel much need to confirm a schedule on a daily basis. Therefore, the operator is less likely to confirm a schedule or confirms the schedule as formality work. As a result, when a schedule changes, the operator does not notice the change and thus is not able to conduct work under an optimum schedule.
According to the technology described in Japanese Patent Application Laid-open No. 2002-373015, a work order is displayed in list form on a machine tool that is being operated by an operator and an information terminal adjacent to the machine tool. However, an operator is not able to intuitively grasp display contents by such a list-form display and has a need to understand the location and the name of a machine concerned. In addition, when an operator conducts work under the same schedule day by day, he/she assumes that no change occurs in a schedule displayed in list form and thus is likely to omit the confirmation of the schedule. Accordingly, there is a need to present information that is more concise, easily understandable, and does not cause the omission of confirmation to an operator working on site.